Prager U, the producer of the video Peterson tweeted, is a conservative, free-market think tank with a long history of pushing false or misleading information about climate change. (The "U" is designed to make it sound like an academic organization. It is not.) The "expert" in this video is Richard Lindzen, an MIT atmospheric physicist who has made a career of downplaying and nay-saying the causes and dangers of global climate change. While the consensus that climate change is caused by the burning of fossil fuels is near-universal among climate scientists, Lindzen—standing nearly alone in the field—disagrees. Penn State climate scientist Michael Mann wrote about Lindzen in his seminal text, The Hockey Stick and the Climate Wars:

Lindzen— who also has received money from fossil fuel interests—is perhaps best known for his controversial views that climate models grossly overestimate the warming effect of increasing greenhouse gas concentrations. It all has to do with the issue of climate feedbacks. Feedbacks, as we have seen, are mechanisms within the climate system that can act either to amplify (positive feedback) or diminish (negative feedback) the warming expected from increasing greenhouse gas concentrations. If a climate scientist has spent a career looking for missing feedbacks in climate models that are always of the same sign (positive for a “true believer” and negative for a “denier”), one might reasonably suspect that the endeavor has not been entirely objective. (Ironically, the one missing feedback I’ve argued for in the climate system is a negative one—a rather inconvenient fact for those who would like to label me a “climate change alarmist.”)

Lindzen has made a career of searching for missing feedbacks, but apparently only negative ones. Indeed, it seems as if he has never met a negative feedback he didn’t like. And he has been quick to trumpet his claims of newly found negative feedbacks in op-eds, opinion pieces, and public testimony, arguing time and again that his findings point to an overestimation of warming by models and are an indication that climate change is an overblown problem. Yet each of his past claims has evaporated under further scrutiny.

For years, Lindzen has argued that hypothesized but as yet unestablished negative feedbacks in the climate system will offset the very large positive feedbacks arising from increased evaporation of water into the atmosphere and melting of snow and ice associated with global warming. He has argued that a doubling of CO2 concentrations will consequently only raise global average temperatures by roughly 1oC (and with zero uncertainty!). Yet the diversity of evidence from the paleoclimate and modern climate record suggests that less than 2oC warming for CO2 doubling is highly unlikely.

In 1990, Lindzen argued that a drying and cooling of the upper troposphere would mitigate global warming but later in effect conceded that further work had demonstrated that the mechanism he had proposed was not viable. In 2001 he promoted a new hypothesis, the so-called “iris” effect, in which warming ocean temperatures would supposedly lead to fewer high clouds, causing surface temperatures to cool down. Once again, this hypothesis didn’t hold up under scrutiny by other scientists.

Undeterred, Lindzen claimed to find evidence for an additional, new negative cloud feedback, this time based on a putative statistical relationship between tropical sea surface temperatures and satellite measurements of the radiation escaping to space. He claimed that when the tropics warm up, there are more low reflective clouds, causing more solar radiation to be returned to space, thus tending to cool the surface. When climate researcher Kevin Trenberth of the National Center for Atmospheric Research (NCAR) and his collaborators examined Lindzen’s claims closely,50 however, they found the data points Lindzen had chosen to be curiously selective, and the claimed relationship not supported when a more objectively chosen sample was used.51 A subsequent analysis by other researchers concluded that the available data may actually support a positive overall cloud feedback, not a negative one.

"Lindzen long ago discredited himself as a messenger on climate," Mann told me in an email. "He engages in bad faith tropes rather than legitimate scientific discourse. What makes Lindzen so dangerous as an agent of denial is that he appears to have impressive credentials but his claims about climate change are vacuous and ill-founded. The denial machine relishes the opportunity to launder its denialist rhetoric through the imprimatur of an MIT professor/National Academy member. Lindzen gives them that opportunity."

Lindzen, who, as Mann noted in his book, has received funding from fossil fuel interests, is an outlier. He's the MD who thinks vaccines cause autism; the geologist who believes in crystal healing. It's not common, but it does happen. Despite what Lindzen claims, the science on climate change has long since been settled, and when someone like Jordan Peterson, who has legions of fans and an outsized influence in this world, cites Richard Lindzen and Prager U as a reputable source, he does a disservice to himself, his viewers, and everyone who doesn't want to watch Miami disappear into the Atlantic. Most of Jordan Peterson's platitudes are, I think, ultimately harmless, but denying the connection between fossil fuels and climate change perpetuates an ideology that is, right now, increasing human suffering. There is something deeply wrong with that.

Jordan Peterson, Richard Lindzen, Donald Trump, and his cronies in government and industry may be happy to stick their heads in the sand and ignore reality, but climate change is no longer up for debate. We can see and feel it: Floods, fires, droughts, and other disasters are bigger, more frequent, and more destructive. Need proof? Go to California, where deadly, destructive, early season wildfires are now the new normal. Go to Houston or Puerto Rico or Syria, where drought connected to climate change led to a worldwide humanitarian crisis. Or ask the military, which knows that climate change threatens stability both at home and abroad, even if the commander in cheif doesn't.

Climate change is here, and instead of wasting time arguing with the people who refuse to acknowledge it, it's high time people, industry, and—especially—the U.S. government, take real steps to prepare for it. So, Jordan Peterson, the next time you're tempted to throw in your two cents on climate change, maybe check with a reputable source, and consider the consequences, before you do it.

To get this delivered to your inbox, subscribe to The Stranger's Slog AM/PM newsletter.